A recent study from the World Health Organizationrevealed that iron (Fe) deficiency anemia not only accounts for the mostprevalent nutrition disorder by affecting 2 billion people, but also for theonly one significantly present in industrialized countries. Approximately everyother pregnant woman as well as 40% of children under the age of six areaffected, when living in developing countries(www.who.
int/nutrition/topics/ida/en). Often people that live in rural placeshave reduced access to a well-balanced diet, dietary supplements or fortifiedstaples. Especially in regions with prevailing malnutrition due to the lack ofaccessibility of high quality nutritious food, numbers of affected people peak (Saltzman et al., 2013; Naranjo?Arcos and Bauer, 2016).In humans, approximately 70% of the Fe is needed forthe production of hemoglobin and hence is involved in erythrocyte-mediatedoxygen transport in the blood whereas roughly 4% is needed for the myoglobin-mediatedtransport within the muscle cells. The remaining Fe is utilized for energyproduction (Scrimshaw, 1984).
Hence, Fe deficiency anemia canhave a severe impact on the physical well-being and overall health. Forinstance, Fe deficiency diminishes infection resistance by impairing the immunesystem, alters cognitive performance, impairs growth and physical performance (Scrimshaw, 1984). One long-term and cost-efficient way to counteractthis problem is to increase the amount of Fe in food staples. This can be doneby selective breeding or genetical modification of plants, in order to enrich theiredible parts with the needed Fe. This strategy however can only succeed ifcertain basic principles are preserved, such as the combination of nutrientenrichment with high yield (ensuring profitability), a decrease in Fedeficiency anemia in humans (ensuring efficiency) as well as acceptance byfarmers (ensuring applicability) (Bouis et al., 2011; Saltzman et al.
, 2013). Thisbiofortification approach has been applied e.g.in rice plants by overexpressing Fe storage, homeostasis, uptake, translocationor transportation genes (Masuda et al., 2013). Recently, a new variety of beans,which are rich in Fe, has successfully been reported to increase Fe levels inRwandan women, highlighting the potential of biofortification (Haas et al., 2016).For a successful application of this promising tool toenhance bio-available nutrients in staple food, it is needed to understand theimportance of nutrients for plants in general and to decipher plant nutrient uptakeand homeostasis systems in-depth.